diff --git a/include/sys.h b/include/sys.h
new file mode 100644
index 0000000..0a7044e
--- /dev/null
+++ b/include/sys.h
@@ -0,0 +1,16 @@
+#pragma once
+
+// Bluejay System Calls
+
+#define SYS_GIVEUP 0x100
+
+/// Bluejay interrupt number
+#define SYS_INT 0x80
+
+/**
+ * @brief Gives up the current threads remaining CPU time. Unless you have set
+ * the thread to waiting, it will resume next time the scheduler decides it's
+ * its turn. The behaviour is identical to if the thread had just run out of
+ * time naturally.
+ */
+extern void sys_giveup();